/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: CastExpr.java,v 1.2.4.1 2005/09/12 10:06:35 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.IF_ICMPNE;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.SIPUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MultiHashtable;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xml.internal.dtm.Axis;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 * @author Erwin Bolwidt <ejb@klomp.org>
 */
final class CastExpr extends Expression {

  private final Expression _left;

  /**
   * Legal conversions between internal types.
   */
  static private MultiHashtable InternalTypeMap = new MultiHashtable();

  static {
    // Possible type conversions between internal types
    InternalTypeMap.put(Type.Boolean, Type.Boolean);
    InternalTypeMap.put(Type.Boolean, Type.Real);
    InternalTypeMap.put(Type.Boolean, Type.String);
    InternalTypeMap.put(Type.Boolean, Type.Reference);
    InternalTypeMap.put(Type.Boolean, Type.Object);

    InternalTypeMap.put(Type.Real, Type.Real);
    InternalTypeMap.put(Type.Real, Type.Int);
    InternalTypeMap.put(Type.Real, Type.Boolean);
    InternalTypeMap.put(Type.Real, Type.String);
    InternalTypeMap.put(Type.Real, Type.Reference);
    InternalTypeMap.put(Type.Real, Type.Object);

    InternalTypeMap.put(Type.Int, Type.Int);
    InternalTypeMap.put(Type.Int, Type.Real);
    InternalTypeMap.put(Type.Int, Type.Boolean);
    InternalTypeMap.put(Type.Int, Type.String);
    InternalTypeMap.put(Type.Int, Type.Reference);
    InternalTypeMap.put(Type.Int, Type.Object);

    InternalTypeMap.put(Type.String, Type.String);
    InternalTypeMap.put(Type.String, Type.Boolean);
    InternalTypeMap.put(Type.String, Type.Real);
    InternalTypeMap.put(Type.String, Type.Reference);
    InternalTypeMap.put(Type.String, Type.Object);

    InternalTypeMap.put(Type.NodeSet, Type.NodeSet);
    InternalTypeMap.put(Type.NodeSet, Type.Boolean);
    InternalTypeMap.put(Type.NodeSet, Type.Real);
    InternalTypeMap.put(Type.NodeSet, Type.String);
    InternalTypeMap.put(Type.NodeSet, Type.Node);
    InternalTypeMap.put(Type.NodeSet, Type.Reference);
    InternalTypeMap.put(Type.NodeSet, Type.Object);

    InternalTypeMap.put(Type.Node, Type.Node);
    InternalTypeMap.put(Type.Node, Type.Boolean);
    InternalTypeMap.put(Type.Node, Type.Real);
    InternalTypeMap.put(Type.Node, Type.String);
    InternalTypeMap.put(Type.Node, Type.NodeSet);
    InternalTypeMap.put(Type.Node, Type.Reference);
    InternalTypeMap.put(Type.Node, Type.Object);

    InternalTypeMap.put(Type.ResultTree, Type.ResultTree);
    InternalTypeMap.put(Type.ResultTree, Type.Boolean);
    InternalTypeMap.put(Type.ResultTree, Type.Real);
    InternalTypeMap.put(Type.ResultTree, Type.String);
    InternalTypeMap.put(Type.ResultTree, Type.NodeSet);
    InternalTypeMap.put(Type.ResultTree, Type.Reference);
    InternalTypeMap.put(Type.ResultTree, Type.Object);

    InternalTypeMap.put(Type.Reference, Type.Reference);
    InternalTypeMap.put(Type.Reference, Type.Boolean);
    InternalTypeMap.put(Type.Reference, Type.Int);
    InternalTypeMap.put(Type.Reference, Type.Real);
    InternalTypeMap.put(Type.Reference, Type.String);
    InternalTypeMap.put(Type.Reference, Type.Node);
    InternalTypeMap.put(Type.Reference, Type.NodeSet);
    InternalTypeMap.put(Type.Reference, Type.ResultTree);
    InternalTypeMap.put(Type.Reference, Type.Object);

    InternalTypeMap.put(Type.Object, Type.String);

    InternalTypeMap.put(Type.Void, Type.String);
  }

  private boolean _typeTest = false;

  /**
   * Construct a cast expression and check that the conversion is
   * valid by calling typeCheck().
   */
  public CastExpr(Expression left, Type type) throws TypeCheckError {
    _left = left;
    _type = type;           // use inherited field

    if ((_left instanceof Step) && (_type == Type.Boolean)) {
      Step step = (Step) _left;
      if ((step.getAxis() == Axis.SELF) && (step.getNodeType() != -1)) {
        _typeTest = true;
      }
    }

    // check if conversion is valid
    setParser(left.getParser());
    setParent(left.getParent());
    left.setParent(this);
    typeCheck(left.getParser().getSymbolTable());
  }

  public Expression getExpr() {
    return _left;
  }

  /**
   * Returns true if this expressions contains a call to position(). This is
   * needed for context changes in node steps containing multiple predicates.
   */
  public boolean hasPositionCall() {
    return (_left.hasPositionCall());
  }

  public boolean hasLastCall() {
    return (_left.hasLastCall());
  }

  public String toString() {
    return "cast(" + _left + ", " + _type + ")";
  }

  /**
   * Type checking a cast expression amounts to verifying that the
   * type conversion is legal. Cast expressions are created during
   * type checking, but typeCheck() is usually not called on them.
   * As a result, this method is called from the constructor.
   */
  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    Type tleft = _left.getType();
    if (tleft == null) {
      tleft = _left.typeCheck(stable);
    }
    if (tleft instanceof NodeType) {
      tleft = Type.Node;  // multiple instances
    } else if (tleft instanceof ResultTreeType) {
      tleft = Type.ResultTree; // multiple instances
    }
    if (InternalTypeMap.maps(tleft, _type) != null) {
      return _type;
    }
    // throw new TypeCheckError(this);
    throw new TypeCheckError(new ErrorMsg(
        ErrorMsg.DATA_CONVERSION_ERR, tleft.toString(), _type.toString()));
  }

  public void translateDesynthesized(ClassGenerator classGen,
      MethodGenerator methodGen) {
    FlowList fl;
    final Type ltype = _left.getType();

    // This is a special case for the self:: axis. Instead of letting
    // the Step object create and iterator that we cast back to a single
    // node, we simply ask the DOM for the node type.
    if (_typeTest) {
      final ConstantPoolGen cpg = classGen.getConstantPool();
      final InstructionList il = methodGen.getInstructionList();

      final int idx = cpg.addInterfaceMethodref(DOM_INTF,
          "getExpandedTypeID",
          "(I)I");
      il.append(new SIPUSH((short) ((Step) _left).getNodeType()));
      il.append(methodGen.loadDOM());
      il.append(methodGen.loadContextNode());
      il.append(new INVOKEINTERFACE(idx, 2));
      _falseList.add(il.append(new IF_ICMPNE(null)));
    } else {

      _left.translate(classGen, methodGen);
      if (_type != ltype) {
        _left.startIterator(classGen, methodGen);
        if (_type instanceof BooleanType) {
          fl = ltype.translateToDesynthesized(classGen, methodGen,
              _type);
          if (fl != null) {
            _falseList.append(fl);
          }
        } else {
          ltype.translateTo(classGen, methodGen, _type);
        }
      }
    }
  }

  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final Type ltype = _left.getType();
    _left.translate(classGen, methodGen);
    if (_type.identicalTo(ltype) == false) {
      _left.startIterator(classGen, methodGen);
      ltype.translateTo(classGen, methodGen, _type);
    }
  }
}
